MRPpohjaiset

MRP-based planning, or MRPpohjaiset, is a manufacturing planning approach that determines what materials are needed, in what quantities, and when they must be available to meet a production schedule. It relies on three core inputs: a bill of materials (BOM) that lists components for each end product, a master production schedule (MPS) that specifies when products are to be manufactured, and current inventory data including lead times. The process is time-phased, converting demand into planned orders across future time periods to synchronize procurement and production with demand.

The key inputs for an MRP run include the BOM, the MPS, inventory status, lead times, and any demand forecasts or customer orders. The output consists of planned orders for purchases and factory production, release schedules for suppliers, and exception messages highlighting issues such as late deliveries or material shortages. MRP can be implemented as a stand-alone concept or as part of broader manufacturing resource planning systems.

MRP-based approaches are often contrasted with MRP II and ERP, which extend the concept by incorporating capacity planning, shop-floor control, and broader enterprise processes. While MRP focuses on material availability, MRP II and ERP aim to align material planning with capacity, scheduling, and supplier collaboration.

Benefits of MRP-based systems include improved material availability, reduced excess inventory, and better adherence to delivery schedules through better visibility. Limitations depend on data quality and process discipline: inaccurate BOMs, erroneous lead times, forecast errors, and frequent schedule changes can reduce effectiveness and require ongoing data maintenance and system tuning. Historically, MRP originated in the 1960s and evolved into more integrated planning approaches in later decades.